I feel achy and tired. How do I know if I have a cold or the flu?

A:

The flu can be serious, so it’s smart to know the difference. The main clue to consider is the severity of your illness.

The flu often leaves you so achy and tired that it’s difficult to get out of bed. You’ll also feel sick from five to seven days. Other flu symptoms include high fever, cough, runny nose, nausea, vomiting, chills and headache.

With a seasonal cold, you may feel achy for a day or two and only have congestion, or a cough and runny nose.

Regardless, most healthy people who catch a cold or the flu don’t need to see a doctor. They will recover on their own by staying home, getting plenty of rest and drinking lots of fluids. (Going to a doctor’s office, on the other hand, puts you at risk for catching more dangerous strains of flu or passing your germs on to others, according to the Centers for Disease Control.)

There are some exceptions, however. Pregnant women, small children, adults older than 65 and those with a chronic illness -- asthma, diabetes, heart disease -- should call a doctor within 48 hours of getting the flu. They are at a higher risk for complications and may need medication. Also, anyone who has trouble breathing or suffers nonstop vomiting or confusion should go to the emergency room. These symptoms signal a more serious problem.

The bottom line: If you are concerned about the severity of your illness, call your physician. He or she will tell you if you should seek medical attention.

Dr. Zachary Rubin is an assistant clinical professor in the Division of Infectious Diseases at the University of California in Los Angeles. He is also a hospital epidemiologist at the Santa Monica UCLA Medical Center. He has previously contributed to Life & Beauty Weekly.